How can I will identify the different classes of IP address? I have learnt that........
Class A:
1st Octet 2nd Octet 3rd Octet 4th Octet
Network ID Host ID Host ID Host ID

Class B:

1st Octet 2nd Octet 3rd Octet 4th Octet
Network ID Network ID Host ID Host ID

Class c:

1st Octet 2nd Octet 3rd Octet 4th Octet
Network ID Network ID Network ID Host ID

Bu this is confucing me..........
Determining the Class of an IP Address
 We can find the class of an IP address when the given address is either in binary notation or in dotted-decimal notation.
 If the address is given in binary notation, the first few bits can immediately tell us the class of the address.

If the first bit of an IP address is 0 , it is class A address
If the first two bits of an IP address is 10 , it is class B address
If the first three bits of an IP address is 110 , it is class C address
If the first four bits of an IP address is 1110 , it is class D address
If the first four bits of an IP address is 1111 , it is class E address

 If the address is given in dotted-decimal notation, the first byte defines the class.

If the value of first octet is between 0 to 127 , it is class A address
If the value of first octet is between 128 to 191 , it is class B address
If the value of first octet is between 192 to 223 , it is class C address
If the value of first octet is between 224 to 239 , it is class D address
If the value of first octet is between 240 to 255 , it is class E address

Example:
Find the class of each address given below:
a) 01101111 00111000 00101101 01001110
b) 11001111 00111110 00101001 01000111
c) 221.34.7.8
d) 15.34.127.89
e) 255.67.243.190

Solution:
a) The first bit is zero. So, this is class A address.
b) The first three bit is 110. So, this is class C address
c) The first octet is 221 (between 192 and 223). So, this is class C address.
d) The first octet is 15 (between 0 and 127). So, this is class A address.
e) The first octet is 255 (between 240 and 255). So, this is class E address.

Can any one help me?

If the 1st Octet,

0-126 - Class A
128-191 - Class B
192-223 - Class C
224-239 - Class D
240-255 - Class E

I think you have done all the Home work,I think you have already know the Answers.
But further. This is class full IP Addresses, …

## All 7 Replies

To me it looks like you have all the answers there, so what exactly do you need help with?

I am confused about how to identify the class of IP address?

But you just explained how in your question, so I'm not quite sure what you confused about

If the 1st Octet,

0-126 - Class A
128-191 - Class B
192-223 - Class C
224-239 - Class D
240-255 - Class E

I think you have done all the Home work,I think you have already know the Answers.
But further. This is class full IP Addresses, So these days we are using Classless IP Addresses by Sub netting and Super netting.

You can google it, there are good explanation you can find it from there.

Good Luck

How can I will identify the different classes of IP address? I have learnt that........
Class A:
1st Octet 2nd Octet 3rd Octet 4th Octet
Network ID Host ID Host ID Host ID

Class B:

1st Octet 2nd Octet 3rd Octet 4th Octet
Network ID Network ID Host ID Host ID

Class c:

1st Octet 2nd Octet 3rd Octet 4th Octet
Network ID Network ID Network ID Host ID

Bu this is confucing me..........
Determining the Class of an IP Address
 We can find the class of an IP address when the given address is either in binary notation or in dotted-decimal notation.
 If the address is given in binary notation, the first few bits can immediately tell us the class of the address.

If the first bit of an IP address is 0 , it is class A address
If the first two bits of an IP address is 10 , it is class B address
If the first three bits of an IP address is 110 , it is class C address
If the first four bits of an IP address is 1110 , it is class D address
If the first four bits of an IP address is 1111 , it is class E address

 If the address is given in dotted-decimal notation, the first byte defines the class.

If the value of first octet is between 0 to 127 , it is class A address
If the value of first octet is between 128 to 191 , it is class B address
If the value of first octet is between 192 to 223 , it is class C address
If the value of first octet is between 224 to 239 , it is class D address
If the value of first octet is between 240 to 255 , it is class E address

Example:
Find the class of each address given below:
a) 01101111 00111000 00101101 01001110
b) 11001111 00111110 00101001 01000111
c) 221.34.7.8
d) 15.34.127.89
e) 255.67.243.190

Solution:
a) The first bit is zero. So, this is class A address.
b) The first three bit is 110. So, this is class C address
c) The first octet is 221 (between 192 and 223). So, this is class C address.
d) The first octet is 15 (between 0 and 127). So, this is class A address.
e) The first octet is 255 (between 240 and 255). So, this is class E address.

Can any one help me?

hi

maybe you dont know that in the first octet of the ip address contains 8 bits, in those bits there is an equivalent decimal number.

128 64 32 16 8 4 2 1

convert the decimal number into binary and check which of the two leftmost bits is 1's

if you have an ip add of 155.2.2.2, convert the 155 to binary. start adding numbers from left to right

1 0 0 1 1 0 1 1

as you can see that the leftmost bit is 1 and 0 on the other side which it makes the class of this ip is B

You are actually suppose to add all the bits of the 1st octet in order to find the decimal value for it then you compare it to see in which range it lies and you will know what class it is. All the above mentioned ways work, it's up to you to decide which one you prefer

I exactly dont know what you are asking

You have explained the answer in better way.

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